Stereochemistry of peptides containing 1-aminocyclopentane carboxylic acid (Acc5). Solution and solid state conformations of Boc-Acc5-Acc5-NHMe.

The conformational analysis of a protected homodipeptide of 1-aminocyclopentanecarboxylic acid (Acc5) has been carried out. 1H-nmr studies establish a ?-turn conformation for Boc-Acc5-Acc5-NHMe in chloroform and dimethylsulfoxide solutions involving the methylamide NH in an intramolecular hydrogen bond. Supportive evidence for the formation of an intramolecular hydrogen bond is obtained from ir studies. X-ray diffraction studies reveal a type III ?-turn conformation in the solid state stabilized by a 4 ? 1 hydrogen bond between the Boc CO and methylamide NH groups. The ?,? values for both Acc5 residues are close to those expected for an ideal 310-helical conformation (?? ± 60°, ?? ±30°).

Conformations of the amino terminal tetrapeptide of emerimicins and antiamoebin in solution and in the solid state

The conformations of Boc-l-Phe-(AiB)3-OH (1) and Boc-l-Phe-(Aib)3-OMe (2) which correspond to the amino terminal sequence of the emerimicins and antiamoebins have been studied in solution using 270 MHz 1H n.m.r. In dimethyl sulphoxide solution both peptides show the presence of two strongly solvent shielded Aib NH groups, consistent with a consecutive β-turn conformation, involving the Aib(3) and Aib(4) NH groups in intramolecular 4 → I hydrogen bonds. This folded conformation is maintained for 2 in chloroform solution. Nuclear Overhauser effect studies provide evidence for a Type II Phe-Aib β-turn. An X-ray diffraction study of Boc-(d,l)-Phe-(Aib)3-OH establishes a single type III(III′) β-turn conformation with Aib(2)-Aib(3) as the corner residues. A single intramolecular 4 → I hydrogen bond between Phe(I) CO and Aib(4) NH groups is observed in the crystal. The solution conformation may incorporate a consecutive type II-III′ structure for the Phe(1)-Aib(2)-Aib(3) segment, with the initial type II β-turn being destabilized by intermolecular interactions in the solid state.

Precise measurement of hyperfine structure in the 2P(1/2) state of Li-7 using saturated-absorption spectroscopy

We report a precise measurement of the hyperfine interval in the 2P(1/2) state of Li-7. The transition from the ground state (D-1 line) is accessed using a diode laser and the technique of saturated-absorption spectroscopy in hot Li vapor. The interval is measured by locking an acousto-optic modulator to the frequency difference between the two hyperfine peaks. The measured interval of 92.040(6) MHz is consistent with an earlier measurement reported by us using an atomic-beam spectrometer Das and Natarajan, J. Phys. B 41, 035001 (2008)]. The interval yields the magnetic dipole constant in the P-1/2 state as A = 46.047(3), which is discrepant from theoretical calculations by > 80 kHz.

Activity–Composition Relations in the Nickel Oxide–Magnesium Oxide System at 1300 K by the Solid-State Galvanic Cell Technique

The activity of NiO in NiO-MgO rock salt solid solution has been measured at 1300 K by employing a solid-state galvanic cell: Pt,Ni+ NiO||(CaO)ZrO2||Ni + (Nix,Mgl-x)O, Pt. A high-density tube of Zr02-15 mol% CaO has been used as the solid electrolyte for the emf measurements. The activities of the component oxides in the rock salt solid solution exhibit negative deviation from ideality at the temperature of investigation. The solid solution obeys regular solution behavior at 1300 K. The value of the regular solution parameter is found to be -12000 ((l000) J mol-1. The composition dependence of ΔGEx obtained in this study agrees reasonably well with the calorimetric data reported in the literature for NiO-MgO solid solution.

Photochromism of alkylisophthalaldehydes in the solid state: structure–reactivity correlations

The crystal and molecular structures of the photochromic compounds 2,5-dimethylisophthalaldehyde (I) and 5-isopropyl-2-methylisophthalaldehyde (II) have been determined by single crystal X-ray analyses. The intramolecular gamma-hydrogen abstraction process involved in the photoenolisation of I and II in the solid state has been rationalised in the light of relevant geometrical parameters.

A simple n-state model for water

A simple n-state configurational excitation model which takes into account the presence of weakly connected pentamer units in liquid water is proposed. The model has features of both the “continuum” and “mixture” models. Calculations based on this model satisfactorily account for the important, diagnostic thermodynamic properties of water such as the density maximum, fraction of monomers and so on.

Pes study of spin-state transitions in d6 transition metal complexes and oxides

Transitions from the low-to the high-spin state in Fe2+ and Co3+ compounds have been examined by X-ray and UV photoelectron spectroscopy. It has been shown that the core-level bands in XPES, in particular the metal 3s band, as well as the valence bands, are diagnosis in the study of spin-state transitions.

Vain hätapua? : Taloudellinen avustaminen diakoniatyön professionaalisen itseymmärryksen ilmentäjänä

Financial Help Alone? Financial help as an exponent of professional diaconal work One essential form of helping people in the Evangelical Lutheran Church s diaconal work is providing economic aid. It can be seen as work which is in accordance with the spirit of the Church Order (4:3). One of the tasks of diaconal work, determined by the Church Order, is to help those whose distress is the greatest and who have no other source of help. This financial support has become a permanent and essential working method, which has also created tension of various kinds. Financial support has been criticized, especially when the support has been used to fill a gap in the social services provided by the government. It has been argued that diaconal work has been forced to take on responsibility for tasks that belong to the welfare state. The tensions involved in the financial support of diaconal work do not only concern the patching up and supplementing of the deficiencies in the welfare state s services but also the question of diaconal workers self-understanding of financial support and how it relates to their professionalism. In this thesis, I examine the experiences and visions diaconal workers have concerning financial support in their work with clients. The viewpoint of my work is the diaconal workers own experiences and interpretations of the meaning of financial support in customer service. In the articles of my thesis, I examined the meanings that diaconal workers gave to financial support in the aspects of work motivation, empowerment, expertise and tensions. The research material of my articles consists of three different data, which are theme interviews from diaconal workers, a survey from diaconal workers of Espoo and a diaconal barometer of 2009. I have analysed the theme interviews and the survey using qualitative content analysis. The results of my articles showed that diaconal workers motivation in tasks concerning economic aid was sustained by the nature and spiritual aspects of support activities. Work that supported empowerment through financial assistance meant influencing the client s personal life, community and local ties and structural circumstances of the surrounding society. Diaconal workers expertise in financial support work can be characterised as horizontal, which means that the expertise was built on acknowledging the client s dignity, the uniqueness of the client s life situation and listening to the client s own voice. Diaconal workers were also experts in community and area-based work. The tensions in financial support work are linked to its unofficial and undefined role in the field of social welfare and the inability of other aiding parties to respond to their duties. The results of my thesis on the experiences and visions of financial support reveal that it is multilateral and multidimensional. Diaconal workers used financial support to help the clients, taking into account their individual, communal, social and spiritual context. The professionalism of this financial support is reflectively related to the client s need of help and the spontaneity and unexpectedness of the situation. Support work was deeply bound to diaconal workers experiences of spirituality as the basic value in their work, the foundation of their idea of humanity and their method of helping others. In different tasks of financial support diaconal workers balanced between traditional, individual client work based on caritas and working methods which are based on supporting the individual s empowerment and active citizenship, as in postmodern social work. Diaconal workers experiences of financial support illustrated the transition or turning point in the professionalism of diaconal work, which involves finding one s own, stronger and clearer professional identity than earlier with respect to other helpers in society. Creating a unique identity is part of the empowerment process of diaconal work, in which it must define its professional role by itself. In postmodern pluralism and the fragmented context of diaconal activities, the question arose as to whether the spiritual traditions and traditional values of diaconal work support the modifications and adaptations needed in new, unpredictable situations. Diaconal work is said to be fast to react, able to predict changes and adapt to those changes. To preserve its sensitive reactive ability, also in the complex postmodern world, it must retain its own views and orientations. Otherwise, the distinctive values and traditions of diaconal work might sustain static diaconal work, employee-centeredness and a smug attitude when defining beneficiaries and needs, which highlights the paternalism of diaconal work. Such paternalism may complicate the progress of working methods which are based on empowerment and citizenship.

Models for spin-state transitions in solids

The model for spin-state transitions described by Bari and Sivardiere (1972) is static and can be solved exactly even when the dynamics of the lattice are included; the dynamic model does not, however, show any phase transition. A coupling between the octahedra, on the other hand, leads to a phase transition in the dynamical two-sublattice displacement model. A coupling of the spin states to the cube of the sublattice displacement leads to a first-order phase transition. The most reasonable model appears to be a two-phonon model in which an ion-cage mode mixes the spin states, while a breathing mode couples to the spin states without mixing. This model explains the non-zero population of high-spin states at low temperatures, temperature-dependent variations in the inverse susceptibility and the spin-state population ratio, as well as the structural phase transitions accompanying spin-state transitions found in some systems.

Interior Medial Axis Transform computation of 3D objects bound by free-form surfaces

This paper presents an algorithm for generating the Interior Medial Axis Transform (iMAT) of 3D objects with free-form boundaries. The algorithm proposed uses the exact representation of the part and generates an approximate rational spline description of the iMAT. The algorithm generates the iMAT by a tracing technique that marches along the object's boundary. The level of approximation is controlled by the choice of the step size in the tracing procedure. Criteria based on distance and local curvature of boundary entities are used to identify the junction points and the search for these junction points is done in an efficient way. The algorithm works for multiply-connected objects as well. Results of the implementation are provided. (C) 2010 Elsevier Ltd. All rights reserved.

Rate Control State-of-the-art Survey

The majority of Internet traffic use Transmission Control Protocol (TCP) as the transport level protocol. It provides a reliable ordered byte stream for the applications. However, applications such as live video streaming place an emphasis on timeliness over reliability. Also a smooth sending rate can be desirable over sharp changes in the sending rate. For these applications TCP is not necessarily suitable. Rate control attempts to address the demands of these applications. An important design feature in all rate control mechanisms is TCP friendliness. We should not negatively impact TCP performance since it is still the dominant protocol. Rate Control mechanisms are classified into two different mechanisms: window-based mechanisms and rate-based mechanisms. Window-based mechanisms increase their sending rate after a successful transfer of a window of packets similar to TCP. They typically decrease their sending rate sharply after a packet loss. Rate-based solutions control their sending rate in some other way. A large subset of rate-based solutions are called equation-based solutions. Equation-based solutions have a control equation which provides an allowed sending rate. Typically these rate-based solutions react slower to both packet losses and increases in available bandwidth making their sending rate smoother than that of window-based solutions. This report contains a survey of rate control mechanisms and a discussion of their relative strengths and weaknesses. A section is dedicated to a discussion on the enhancements in wireless environments. Another topic in the report is bandwidth estimation. Bandwidth estimation is divided into capacity estimation and available bandwidth estimation. We describe techniques that enable the calculation of a fair sending rate that can be used to create novel rate control mechanisms.

Impedance parameters and the state-of-charge. III. Zinc-manganese dioxide and magnesium-manganese dioxide dry batteries

The problem of non-destructive determination of the state-of-charge of zinc- and magnesium-manganese dioxide dry batteries is examined experimentally from the viewpoint of internal impedance and open-circuit voltage at equilibrium. It is shown that the impedance is mainly charge-transfer controlled at relatively high states-of-charge and progressively changes over to diffusion control as the state-of-charge decreases in the case of zinc-manganese dioxide dry batteries. On the other hand, the impedance is mainly diffusion controlled for undischarged batteries but becomes charge-transfer controlled as soon as there is some discharge in the case of magnesium-manganese dioxide batteries. It is concluded that the determination of state-of-charge is not possible for both types of batteries by the measurement of impedance parameters due to film-induced fluctuations of these parameters. The measurement of open-circuit voltage at equilibrium can be used as a state-of-charge indicator for Zn-MnO2 batteries but not for Mg-MnO2 batteries.

Impedance parameters and the state-of-charge. II. Lead-acid battery

The determination of the state-of-charge of the lead-acid battery has been examined from the viewpoint of internal impedance. It is shown that the impedance is controlled by charge transfer and to a smaller extent by diffusion processes in the frequency range 15–100 Hz. The equivalent series/parallel capacitance as well as the a.c. phase-shift show a parabolic dependence upon the state-of-charge, with a maximum or minimum at 50% charge. These results are explained on the basis of a uniform transmission-line analog equivalent circuit for the battery electrodes.